If you have, you’re not alone. About 25% of the population is affected each year, particularly during the months of December, January and February. For 7% of people the symptoms can actually become debilitating. It’s like a form of winter depression called SAD (Seasonal Affective Disorder). A reduction in daylight hours and a lack of sunlight disrupt our body clocks and may lead to an imbalance in the neurotransmitters serotonin and melatonin.

Winter is characterised by a relative scarcity of food and some animals take the opportunity to hibernate. Their metabolism decreases in order to conserve energy. Although we’ve never hibernated, before the advent of electricity and in particular the light bulb in the 1800s, our activity and sleep was dictated by sunlight. As the number of sunlight hours decreased during the winter months, so did our activity. Our body clocks followed a marked seasonal rhythm.

The artificial light produced by electricity has allowed us to become more productive by helping us keep the same working hours throughout the year. Even though artificial lighting is strong enough to allow us to work and live, it’s much weaker than natural sunlight. As a result, it lacks the strength to regulate our body clocks in the same way that natural sunlight does. We’re now forcing our bodies to awaken when they would naturally be asleep. This burden hasn’t been tolerated well.

Read my next post for some useful tips to help you beat the winter blues.